Charlotte guard Terrence Williams, center, goes to the basket against MichiganâÂÂs Max Bielfeldt, left, and Jon Horford during the Wolverines' championship game loss in the Puerto Rico Tip-Off on Sunday in San Juan.AP Photo | Ricardo Arduengo

SAN JUAN, Puerto Rico -- The late afternoon temperature in Ann Arbor on Monday is expected to be in the high 20s. The Michigan team bus could be welcomed back by flurries.

Cold reality.

A five-day trip to the shores of San Juan didn’t bring home three wins. This wasn’t expected to be a vacation. Puerto Rico was supposed to be the book that put a Michigan roster previously missing Mitch McGary back on the same page.

Instead there’s this: Glenn Robinson III is now down with a back injury. The extent isn’t known. The specific injury isn’t known, either. Nik Stauskas, too, is heading home on the mend. He tweaked an ankle. A 63-61 loss in the Puerto Rico Tip-Off championship game to Charlotte, a team that previously lost to College of Charleston, is the margarita salt in the wound.

Michigan is left with a 4-2 record.

It took three months for the Wolverines to lose two games a year ago.

Of course, that’s an unfair comparison. That Michigan team had the national player of the year and owned stock in good mojo.

This Michigan team faced second-half, double-digit deficits to both Florida State and Charlotte this weekend. The Wolverines’ offense has only established one constant characteristic through six games: It shoots a lot of 3s.

Following Sunday’s last-second loss to Charlotte, John Beilein plopped down at a table in a back room of Coliseo Roberto Clemente.

“We had adversity tonight like we haven’t had and we just kept plugging away, so it’s all good,” he said.

Some eyes glanced around the room.

“I know that sounds crazy, but it’s all good right now,” he continued, “to come in that environment, play as hard as we did and fight back to have a chance to win it in the end.”

Positive spin aside, Michigan is leaving Puerto Rico with more problems than solutions.

The obvious is Robinson’s status. Beilein is scheduled to meet with the media on Wednesday. All he said regarding the injury Sunday was, “It appears to be something in his back.”

Robinson crashed to the floor with 11:28 left in the first half. He landed flat on his back following a midair collision, leaving the game soon after for the locker room.

Robinson started the second half, but was pulled after two minutes.

“We tried to get him in there as much as we could,” Beilein said. “The advice I was hearing from trainers was to keep him going and after the first time we could see, even when he was out there, he wasn’t moving, and it was going to be a very, very physical game. It wasn’t worth it to risk further injury.”

Stauskas played out the game on his bum ankle. Now attention shifts to the immediate future -- if the ankle could become a lingering problem. Stauskas was U-M’s best player in Puerto Rico by a healthy margin. He led the tournament in scoring at 23.3 points per game and took 18 more free throws than his next closest teammate (Robinson).

Injuries are only the highlighted issues.

There’s more.

If Michigan’s 3-pointers are not falling, the offense can quickly go from great to ghastly. After shooting 14-for-30 from deep in a romp over Long Beach State on Thursday, the Wolverines were 14-of-47 (29.8 percent) against Florida State and Charlotte. No wonder they trailed badly in both.

Against FSU, McGary served as a bailout for the shooting woes.

Not on Sunday.

In his fourth game back since returning from a preseason back injury, McGary looked like an outsider in the U-M offense against Charlotte. He took only five shots, including the first 3 of his career, and two free throws in 30 minutes Sunday. His touches were limited. There was more drifting than playing.

Without McGary scoring, Michigan has little to no post production. Forwards Jordan Morgan and Jon Horford combined for 5-of-14 shooting and 13 points in 60 minutes -- for the entire tournament.

Some of Sunday’s issues were isolated. Foul trouble, especially two early fouls apiece on Caris LeVert and Derrick Walton Jr., rendered U-M without its two primary ballhandlers. The Wolverines were whistled for nine first-half fouls -- a rarity.

They couldn’t overcome it. On Friday, FSU coach Leonard Hamilton said Michigan “played like a team that’s been to the Final Four.” It did indeed. Beilein’s team found a way to win when things went awry.

Not on Sunday. Michigan played like a team undercut by predicaments.

That left it out in the cold.

“We have some very difficult games coming up and this was a great opportunity for us to learn about, hey, every possession is important, each blockout in important, each foul shot is important,” Beilein said. “It hits you hard. We’ve had two games now, between this and Iowa State, we played high level teams. (Charlotte) is a terrific basketball team.”

Brendan F. Quinn covers University of Michigan basketball. Follow him on Twitter for the latest on Wolverines hoops. He can be contacted at bquinn@mlive.com